package com.liuyu.common.framework.lang;


import java.io.InputStream;
import java.security.MessageDigest;

/**
 *
 * @author liuyu
 * @date 2021/8/23 15:46
 */
public class Md5 {

    // private static final int BUFFER_SIZE = 1024 ;

    private static final int S11 = 7;
    private static final int S12 = 12;
    private static final int S13 = 17;
    private static final int S14 = 22;
    private static final int S21 = 5;
    private static final int S22 = 9;
    private static final int S23 = 14;
    private static final int S24 = 20;
    private static final int S31 = 4;
    private static final int S32 = 11;
    private static final int S33 = 16;
    private static final int S34 = 23;
    private static final int S41 = 6;
    private static final int S42 = 10;
    private static final int S43 = 15;
    private static final int S44 = 21;
    private static final int INT_FOUR = 4;
    private static final int INT_63 = 63;
    private static final int INT_64 = 64;
    private static final int INT_4 = 4;

//    private static byte padding[] = {
//	(byte) 0x80, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
//	(byte) 0, (byte) 0, (byte) 0, (byte) 0
//    } ;


    private InputStream in = null;
    private boolean stringp = false;
    private int[] state = null;
    private long count = 0;
    private byte[] buffer = null;
    private final byte[] digest = null;

    public static String stringify(byte[] buf) {
        StringBuffer sb = new StringBuffer(2 * buf.length);
        for (int i = 0; i < buf.length; i++) {
            int h = (buf[i] & 0xf0) >> 4;
            int l = (buf[i] & 0x0f);
            sb.append((char) ((h > 9) ? 'a' + h - 10 : '0' + h));
            sb.append((char) ((l > 9) ? 'a' + l - 10 : '0' + l));
        }
        return sb.toString();
    }

    private final int f(int x, int y, int z) {
        return ((x & y) | ((~x) & z));
    }

    private final int g(int x, int y, int z) {
        return ((x & z) | (y & (~z)));
    }

    private final int h(int x, int y, int z) {
        return (x ^ y ^ z);
    }

    private final int i(int x, int y, int z) {
        return (y ^ (x | (~z)));
    }

    private final int rotateLeft(int x, int n) {
        return ((x << n) | (x >>> (32 - n)));
    }

    private final int fF(int a, int b, int c, int d, int x, int s, int ac) {
        a += (f(b, c, d) + x + ac);
        a = rotateLeft(a, s);
        a += b;
        return a;
    }

    private final int gG(int a, int b, int c, int d, int x, int s, int ac) {
        a += (g(b, c, d) + x + ac);
        a = rotateLeft(a, s);
        a += b;
        return a;
    }

    private final int hH(int a, int b, int c, int d, int x, int s, int ac) {
        a += (h(b, c, d) + x + ac);
        a = rotateLeft(a, s);
        a += b;
        return a;
    }

    private final int iI(int a, int b, int c, int d, int x, int s, int ac) {
        a += (i(b, c, d) + x + ac);
        a = rotateLeft(a, s);
        a += b;
        return a;
    }

    private final void decode(int[] output, byte[] input, int off, int len) {
        int i = 0;
        int j = 0;
        for (; j < len; i++, j += INT_FOUR) {
            output[i] = (((int) (input[off + j] & 0xff))
                    | (((int) (input[off + j + 1] & 0xff)) << 8)
                    | (((int) (input[off + j + 2] & 0xff)) << 16)
                    | (((int) (input[off + j + 3] & 0xff)) << 24));
        }
    }

    private final void transform(byte[] block, int offset) {
        int a = state[0];
        int b = state[1];
        int c = state[2];
        int d = state[3];
        int[] x = new int[16];

        decode(x, block, offset, 64);
        /* Round 1 */
        /* 1 */
        a = fF(a, b, c, d, x[0], S11, 0xd76aa478);
        /* 2 */
        d = fF(d, a, b, c, x[1], S12, 0xe8c7b756);
        /* 3 */
        c = fF(c, d, a, b, x[2], S13, 0x242070db);
        /* 4 */
        b = fF(b, c, d, a, x[3], S14, 0xc1bdceee);
        /* 5 */
        a = fF(a, b, c, d, x[4], S11, 0xf57c0faf);
        /* 6 */
        d = fF(d, a, b, c, x[5], S12, 0x4787c62a);
        /* 7 */
        c = fF(c, d, a, b, x[6], S13, 0xa8304613);
        /* 8 */
        b = fF(b, c, d, a, x[7], S14, 0xfd469501);
        /* 9 */
        a = fF(a, b, c, d, x[8], S11, 0x698098d8);
        /* 10 */
        d = fF(d, a, b, c, x[9], S12, 0x8b44f7af);
        /* 11 */
        c = fF(c, d, a, b, x[10], S13, 0xffff5bb1);
        /* 12 */
        b = fF(b, c, d, a, x[11], S14, 0x895cd7be);
        /* 13 */
        a = fF(a, b, c, d, x[12], S11, 0x6b901122);
        /* 14 */
        d = fF(d, a, b, c, x[13], S12, 0xfd987193);
        /* 15 */
        c = fF(c, d, a, b, x[14], S13, 0xa679438e);
        /* 16 */
        b = fF(b, c, d, a, x[15], S14, 0x49b40821);
        /* Round 2 */
        /* 17 */
        a = gG(a, b, c, d, x[1], S21, 0xf61e2562);
        /* 18 */
        d = gG(d, a, b, c, x[6], S22, 0xc040b340);
        /* 19 */
        c = gG(c, d, a, b, x[11], S23, 0x265e5a51);
        /* 20 */
        b = gG(b, c, d, a, x[0], S24, 0xe9b6c7aa);
        /* 21 */
        a = gG(a, b, c, d, x[5], S21, 0xd62f105d);
        /* 22 */
        d = gG(d, a, b, c, x[10], S22, 0x2441453);
        /* 23 */
        c = gG(c, d, a, b, x[15], S23, 0xd8a1e681);
        /* 24 */
        b = gG(b, c, d, a, x[4], S24, 0xe7d3fbc8);
        /* 25 */
        a = gG(a, b, c, d, x[9], S21, 0x21e1cde6);
        /* 26 */
        d = gG(d, a, b, c, x[14], S22, 0xc33707d6);
        /* 27 */
        c = gG(c, d, a, b, x[3], S23, 0xf4d50d87);
        /* 28 */
        b = gG(b, c, d, a, x[8], S24, 0x455a14ed);
        /* 29 */
        a = gG(a, b, c, d, x[13], S21, 0xa9e3e905);
        /* 30 */
        d = gG(d, a, b, c, x[2], S22, 0xfcefa3f8);
        /* 31 */
        c = gG(c, d, a, b, x[7], S23, 0x676f02d9);
        /* 32 */
        b = gG(b, c, d, a, x[12], S24, 0x8d2a4c8a);

        /* Round 3 */
        /* 33 */
        a = hH(a, b, c, d, x[5], S31, 0xfffa3942);
        /* 34 */
        d = hH(d, a, b, c, x[8], S32, 0x8771f681);
        /* 35 */
        c = hH(c, d, a, b, x[11], S33, 0x6d9d6122);
        /* 36 */
        b = hH(b, c, d, a, x[14], S34, 0xfde5380c);
        /* 37 */
        a = hH(a, b, c, d, x[1], S31, 0xa4beea44);
        /* 38 */
        d = hH(d, a, b, c, x[4], S32, 0x4bdecfa9);
        /* 39 */
        c = hH(c, d, a, b, x[7], S33, 0xf6bb4b60);
        /* 40 */
        b = hH(b, c, d, a, x[10], S34, 0xbebfbc70);
        /* 41 */
        a = hH(a, b, c, d, x[13], S31, 0x289b7ec6);
        /* 42 */
        d = hH(d, a, b, c, x[0], S32, 0xeaa127fa);
        /* 43 */
        c = hH(c, d, a, b, x[3], S33, 0xd4ef3085);
        /* 44 */
        b = hH(b, c, d, a, x[6], S34, 0x4881d05);
        /* 45 */
        a = hH(a, b, c, d, x[9], S31, 0xd9d4d039);
        /* 46 */
        d = hH(d, a, b, c, x[12], S32, 0xe6db99e5);
        /* 47 */
        c = hH(c, d, a, b, x[15], S33, 0x1fa27cf8);
        /* 48 */
        b = hH(b, c, d, a, x[2], S34, 0xc4ac5665);

        /* Round 4 */
        /* 49 */
        a = iI(a, b, c, d, x[0], S41, 0xf4292244);
        /* 50 */
        d = iI(d, a, b, c, x[7], S42, 0x432aff97);
        /* 51 */
        c = iI(c, d, a, b, x[14], S43, 0xab9423a7);
        /* 52 */
        b = iI(b, c, d, a, x[5], S44, 0xfc93a039);
        /* 53 */
        a = iI(a, b, c, d, x[12], S41, 0x655b59c3);
        /* 54 */
        d = iI(d, a, b, c, x[3], S42, 0x8f0ccc92);
        /* 55 */
        c = iI(c, d, a, b, x[10], S43, 0xffeff47d);
        /* 56 */
        b = iI(b, c, d, a, x[1], S44, 0x85845dd1);
        /* 57 */
        a = iI(a, b, c, d, x[8], S41, 0x6fa87e4f);
        /* 58 */
        d = iI(d, a, b, c, x[15], S42, 0xfe2ce6e0);
        /* 59 */
        c = iI(c, d, a, b, x[6], S43, 0xa3014314);
        /* 60 */
        b = iI(b, c, d, a, x[13], S44, 0x4e0811a1);
        /* 61 */
        a = iI(a, b, c, d, x[4], S41, 0xf7537e82);
        /* 62 */
        d = iI(d, a, b, c, x[11], S42, 0xbd3af235);
        /* 63 */
        c = iI(c, d, a, b, x[2], S43, 0x2ad7d2bb);
        /* 64 */
        b = iI(b, c, d, a, x[9], S44, 0xeb86d391);

        state[0] += a;
        state[1] += b;
        state[2] += c;
        state[3] += d;
    }

    private final void update(byte[] input, int len) {
        int index = ((int) (count >> 3)) & 0x3f;
        count += (len << 3);
        int partLen = 64 - index;
        int i = 0;
        if (len >= partLen) {
            System.arraycopy(input, 0, buffer, index, partLen);
            transform(buffer, 0);
            for (i = partLen; i + INT_63 < len; i += INT_64) {
                transform(input, i);
            }
            index = 0;
        } else {
            i = 0;
        }
        System.arraycopy(input, i, buffer, index, len - i);
    }

//    private byte[] end () {
//	byte bits[] = new byte[8] ;
//	for (int i = 0 ; i < 8 ; i++)
//	    bits[i] = (byte) ((count>>>(i*8)) & 0xff) ;
//	int index  = ((int) (count >> 3)) & 0x3f ;
//	int padlen = (index < 56) ? (56 - index) : (120 - index) ;
//	update (padding, padlen) ;
//	update (bits, 8) ;
//	return encode(state, 16) ;
//    }

   
    /**
     *
     *Encode the content.state array into 16 bytes array
     * @author liuyu
     * @date 2021/8/23 18:21
     * @param input
     * @param len
     * @return byte[]
     */
    private byte[] encode(int[] input, int len) {
        byte[] output = new byte[len];
        int i = 0;
        int j = 0;
        for (; j < len; i++, j += INT_4) {
            output[j] = (byte) ((input[i]) & 0xff);
            output[j + 1] = (byte) ((input[i] >> 8) & 0xff);
            output[j + 2] = (byte) ((input[i] >> 16) & 0xff);
            output[j + 3] = (byte) ((input[i] >> 24) & 0xff);
        }
        return output;
    }


    /**
     * Get the digest, for this string digestifier.
     * This method doesn't throw any IOException, since it knows that the
     * underlying stream ws built from a String.
     */


    /**
     * Get the digest, as a proper string.
     */

    public String getStringDigest() {
        if (digest == null) {
            throw new RuntimeException(this.getClass().getName()
                    + "[getStringDigest]"
                    + ": called before processing.");
        }
        return stringify(digest);
    }


    /**
     * Construct a digestifier for the given string.
     * @param input The string to be digestified.
     * @param encoding the encoding name used (such as UTF8)
     */

//    public Md5 (String input, String enc) {
// 	byte bytes [] = null;
//	try {
//	    bytes = input.getBytes (enc);
//	} catch(UnsupportedEncodingException e){
//	    throw new RuntimeException("no "+enc+" encoding!!!");
//	}
//	this.stringp = true ;
//	this.in      = new ByteArrayInputStream (bytes) ;
//	this.state   = new int[4] ;
//	this.buffer  = new byte[64] ;
//	this.count   = 0 ;
//	state[0] = 0x67452301;
//	state[1] = 0xefcdab89;
//	state[2] = 0x98badcfe;
//	state[3] = 0x10325476;
//    }

    /**
     * Construct a digestifier for the given string.
     * @param input The string to be digestified.
     */

    public Md5(String input) {
//	this(input, "UTF8");
    }

    /**
     * Construct a digestifier for the given input stream.
     * @param in The input stream to be digestified.
     */

    public Md5(InputStream in) {
        this.stringp = false;
        this.in = in;
        this.state = new int[4];
        this.buffer = new byte[64];
        this.count = 0;
        state[0] = 0x67452301;
        state[1] = 0xefcdab89;
        state[2] = 0x98badcfe;
        state[3] = 0x10325476;
    }


    public static String encodeByMd5(String s) throws Exception {
        MessageDigest md = MessageDigest.getInstance("Md5");
        md.reset();
        byte[] cryptbyte = md.digest(s.getBytes());
        return byteToString(cryptbyte);
    }

    private static final char[] HEX_DIGITS = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
            'a', 'b', 'c', 'd', 'e', 'f'};

    private static String byteToString(byte[] cryptbyte) {
        int j = cryptbyte.length;
        char[] ac = new char[j * 2];
        int k = 0;

        for (int i = 0; i < j; i++) {
            byte byte0 = cryptbyte[i];
            ac[k++] = HEX_DIGITS[byte0 >>> 4 & 0xf];
            ac[k++] = HEX_DIGITS[byte0 & 0xf];
        }
        return new String(ac);
    }

    public static String binToAscii(byte[] bySourceByte) {
        int len, i;
        byte tb;
        char high, tmp, low;
        String result = new String();
        len = bySourceByte.length;
        for (i = 0; i < len; i++) {
            tb = bySourceByte[i];

            tmp = (char) ((tb >>> 4) & 0x000f);
            if (tmp >= 10) {
                high = (char) ('a' + tmp - 10);
            } else {
                high = (char) ('0' + tmp);
            }
            result += high;
            tmp = (char) (tb & 0x000f);
            if (tmp >= 10) {
                low = (char) ('a' + tmp - 10);
            } else {
                low = (char) ('0' + tmp);
            }
            result += low;
        }
        return result;
    }

}
